Reliable electrical power becomes one of the most wanted factor in modern world industry where operation should be uninterruptible and maximize the cycle of operation, output quality and to avoid losses and damages. Here we are talking about Automatic Transfer Switches (ATS) also known as Automatic Mains Failure (AMF) panel to cater uninterrupted power supply from Mains or backup sources like Diesel gen-set, static ups etc.
Earthing or Grounding of Diesel Generator Plant is important to ensure correct operation of the plant and safety of the people who work over there. Generator neutral (star point) is to be connected by insulated earthing conductor through the neutral earthing link or device to main earthing bar. Neutral earthing conductor is to be suitably sized to carry maximum earth fault current for time it takes the system protection to operate with final conductor temperature not exceeding 160 deg. C, but not less than 30 mm2 per 100 kVA of generator rating, with a minimum of 50 mm2. All emergency power diesel gensets including portable gensets to be connected to grounding conductor.
These drawings show how to install Fire Alarm Break Glass (BG) or Manual Call Point (MCP) on walls. It has to be mounted on back box installed in the wall. This box (embedded or exposed as specified in the concerned section of the specification) has to be connected through GI / PVC conduit that will have the Firetuff or equivalent cable to be looped for other detectors.
A. Ground Rod:
16 mm diameter stainless steel. Driving head is to be high strength steel. Couplings are to be long length silicon bronze, internally threaded. Threads are to be rolled onto rod to ensure uniform layers of copper and strength. Earth rod is to be complete with non-corrosive couplings, head and bolted connector of sufficient size, and number of bolted clamps to connect all cables terminated thereto.
The scope of this specification covers the supply, installation and testing and earthing system of the entire installation and for lightning protection.
Scope of Work of this this sample specification covers the supply, installation, testing and commissioning of all wiring materials for power and lighting in concealed and/or surface conduits.
1. Applicable Standards
The conduits shall conform to IS 9537 I & II or equivalent standards. Switches, Plug Sockets shall conform to IS 3854 and IS 4615, however, contractor shall comply with the latest or superseded versions of IS/BIS to be used for the complete work.
In electrical projects, both construction as well as maintenance, the following terms used on the Drawings, Specifications and in the actual Work site are equivalent and may be used interchangeably: "earth" and "ground"; "earthing" and "grounding". Besides, this article tries to rectify misinterpretation of some important terms often used by people involved in the electrical earthing / grounding work.
A. Protection against Corrosion:
Protect bolted connections against corrosion either hy filling with vaseline or coating with a special anti-corrosion compound and proper capping (Denso tape / grease caps).
Lightning Protection System should be in accordance with BS 6651 and IEC 61024 to protect the building structure and personnel from the risk of a lightning strike. The installation shall comprise air networks connected to roof and down conductors and finally terminated in earth electrodes, via structural re-bars and suitable test points in accordance with the details included on the attached drawings or in the Specification Section.
Low Voltage Switchgear are familiar to every people since they are the controlling mediators between low voltage utilities and equipment with human beings. Be it a common home DB or an isolator or control centres, they all are being manufactured to use untrained people ie., common people. The scope of works shall cover the supply installation, testing and commissioning of main and sub-distribution boards, panel boards, fusible safety switches, circuit breakers etc. Associated minor building works require for the erection of the distribution boards and panels shall be included in the scope of work.